Figure 7. Effect of oxidative and osmotic stress on the viability of C. jejuni 81-176 mutants with defective amino acid catabolism.

(A) Shown is the capability of C. jejuni 81-176 wild-type and the sdaA, putP and peb1A mutants to survive oxidative stress caused by treatment with H₂O₂. Serial dilutions of the bacterial suspensions after the different treatments were spotted on Brucella broth agar plates after the indicated incubation times. (B) The resistance of C. jejuni 81-176 wild-type and its isogenic sdaA, putP and peb1A mutants to variable osmotic stress conditions is presented. Liquid cultures were adjusted to an OD₆₀₀ of 0.1 and serial dilutions were spotted on Mueller Hinton agar plates supplemented with 0%, and 0.5% NaCl.